Power system for and method of operation of magnetically-activated arteriovenous access valve system

ABSTRACT

A power system for and method of operation of an arteriovenous access valve system including two valves positioned near arteriovenous grafts, an actuator assembly in fluid communication with the valves and including a driver assembly, at least one pressure sensor, a separate activator device for driving the driver assembly, and a sensor communications device communicatively coupled to the at least one pressure sensor for wirelessly transmitting pressure measurements. The power system and method also include using an initiator device located in the activator device to power remotely the sensor communications device, for example via near field communication such as via a radio frequency field.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 14/695,241, filed on Apr. 24, 2015, entitled“Magnetically Activated Arteriovenous Access Valve System and RelatedMethods,” which is hereby incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present subject matter relates generally to arteriovenous accessvalve systems and, more particularly, to a needle-free, magneticallyactivated valve system for opening and closing valves positioned at oradjacent to the ends of an arteriovenous graft.

BACKGROUND

The function of kidneys, which are glandular organs located in the upperabdominal cavity of vertebrates, is to filter blood and remove wasteproducts. Specifically, kidneys separate water and waste products ofmetabolism from blood and excrete them as urine through the bladder.Chronic renal failure is a disease of the kidney in which the kidneyfunction breaks down and is no longer able to filter blood and removewaste substances. Should certain toxic waste substances not be removedfrom the blood, the toxic substances may increase to lethalconcentrations within the body.

Hemodialysis is a life-sustaining treatment for patients who have renalfailure. Hemodialysis is a process whereby the patient's blood isfiltered and toxins are removed using an extracorporeal dialysismachine. For hemodialysis to be effective, large volumes of blood mustbe removed rapidly from the patient's body, passed through the dialysismachine, and returned to the patient. A number of operations have beendeveloped to provide access to the circulation system of a patient suchthat patients may be connected to the dialysis machine.

For example, a commonly performed hemodialysis access operation is asubcutaneous placement of an arteriovenous graft, which is made from abiocompatible tube. The biocompatible tube can be made of, for instance,a fluoropolymer such as polytetrafluoroethylene. One end of the tube isconnected to an artery while the other end is connected to a vein. Thearteriovenous graft is typically placed either in the leg or arm of apatient.

Blood flows from the artery, through the graft and into the vein. Toconnect the patient to a dialysis machine, two large hypodermic needlesare inserted through the skin and into the graft. Blood is removed fromthe patient through one needle, circulated through the dialysis machine,and returned to the patient through the second needle. Typically,patients undergo hemodialysis approximately four hours a day, three daysa week.

Various problems, however, have been experienced with the use of anarteriovenous graft. For example, arterial steal occurs when excessiveblood flow through the arteriovenous graft “steals” blood from thedistal arterial bed. Arterial steal can prevent the proper supply ofblood from reaching the extremity of a patient.

To address such problems, systems and processes have been deployed whichcan minimize or prevent complications by closing the arteriovenous graftwhen hemodialysis is not taking place. An example of one such system isdescribed in U.S. Pat. No. 7,025,741 entitled “Arteriovenous accessvalve system and process”, which is hereby incorporated by referenceherein in its entirety for all purposes. These systems and processesutilize valves, such as balloon valves, to force closure of one or moreportions of an arteriovenous graft by pressing the arteriovenous graftwalls together.

However, such implanted valve systems typically require that the valvesbe actuated using one or more hypodermic needles. For example, for asystem including two balloon valves (e.g., a valve positioned at eachend of the arteriovenous graft), two separate needles must be usedinserted through the patient's skin and into corresponding injectionports associated with the valves to allow the balloons to be inflatedand deflated. The use of such needles significantly adds to the ongoingcosts of performing hemodialysis processes. In addition, the needles addto the discomfort level of the patient as the hemodialysis process isbeing performed.

Accordingly, a needle-free, arteriovenous access valve system would bewelcomed in the technology.

SUMMARY

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one aspect, the present subject matter is directed to anarteriovenous access valve system. The system may generally include afirst valve configured to be positioned at or adjacent to an end of anarteriovenous graft and a second valve configured to be positioned at oradjacent to an opposite end of the arteriovenous graft. In addition, thesystem may include an actuator assembly in fluid communication with thefirst and second valves. The actuator assembly may include a housing, adriver assembly positioned within the housing and a drive magnetpositioned within the housing. The drive magnet may be rotatably coupledto the driver assembly such that, when the drive magnet is rotated, thedriver assembly is configured to be rotatably driven so as to supplyfluid to the first and second valves or to draw fluid out of the firstand second valves depending on a rotational direction of the driverassembly.

In another aspect, the present subject matter is directed to anarteriovenous access valve system. The system may generally include afirst valve configured to be positioned at or adjacent to an end of anarteriovenous graft and a second valve configured to be positioned at oradjacent to an opposite end of the arteriovenous graft. The system mayalso include an actuator assembly in fluid communication with the firstand second valves. The actuator assembly may include a housing and adriver assembly positioned within the housing. In addition, the systemmay include an activator device having an activator magnet. Theactivator device may be configured to rotate the activator magnet so asto rotationally drive the driver assembly. Moreover, the driver assemblymay be configured to supply fluid to the first and second valves or drawfluid out of the first and second valves depending on a rotationaldirection at which the driver assembly is being driven.

In a further aspect, the present subject matter is directed to a methodfor operating an arteriovenous access valve system that includes animplemented actuator assembly in fluid communication with first andsecond valves. The method may generally include positioning an externalactivator device in proximity to the implanted actuator assembly,wherein the external activator device includes a rotatable magnet. Inaddition, the method may include rotating the magnet while the externalactivator device is positioned adjacent to the implanted actuatorassembly so as to rotationally drive a driver assembly of the implantedactuator assembly. The driver assembly may be configured to supply fluidto the first and second valves or draw fluid out of the first and secondvalves depending on a rotational direction at which the driver assemblyis being driven.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 illustrates a side view with cut away portions of a human armillustrating one example of the placement of an arteriovenous graft;

FIG. 2 illustrates a simplified, perspective view of one embodiment ofarteriovenous access valve system in accordance with aspects of thepresent subject matter;

FIG. 3 illustrates a perspective view of one embodiment of an actuatorassembly and a corresponding activator device that may be utilizedwithin the disclosed system in accordance with aspects of the presentsubject matter, with various exterior surfaces and/or walls of theassembly being shown as see-through or transparent (e.g., via the dashedlines) to illustrate the internal components of the assembly;

FIG. 4 illustrates another perspective view of the actuator assembly andthe activator device shown in FIG. 3, particularly illustratingcomponents of the actuator assembly in an unactuated position, withvarious exterior surfaces and/or walls of the assembly being shown assee-through or transparent (e.g., via the dashed lines) to illustratethe internal components of the assembly;

FIG. 5 illustrates a further perspective view of the actuator assemblyand the activator device shown in FIG. 3, particularly illustratingcomponents of the actuator assembly in an actuated position, withvarious exterior surfaces and/or walls of the assembly being shown assee-through or transparent (e.g., via the dashed lines) to illustratethe internal components of the assembly;

FIG. 6 illustrates a cross-sectional view of the actuator assembly shownin FIGS. 3-5;

FIG. 7 illustrates a simple line drawing of the actuator assembly shownin FIGS. 3-6, particularly illustrating various exterior surfaces and/orwalls of the assembly as being see-through or transparent (e.g., via thedashed lines) to illustrate the internal components of the assembly;

FIG. 8 illustrates yet another perspective view of the actuator assemblyshown in FIGS. 3-7;

FIG. 9 illustrates a side view of the activator device shown in FIGS.3-5;

FIG. 10 illustrates a cross-sectional view of one embodiment of afluid-actuated balloon valve suitable for use within the disclosedsystem, particularly illustrated the valve in a closed position;

FIG. 11 illustrates another cross-sectional view of the fluid-actuatedballoon valve shown in FIG. 10, particularly illustrated the valve in anopen position;

FIG. 12 illustrates a perspective view of one embodiment of an actuatorassembly and a corresponding activator device (as well as various othersystem components) that may be utilized within the disclosed system inaccordance with aspects of the present subject matter;

FIG. 13 illustrates a perspective view of the actuator assembly shown inFIG. 12, particularly illustrating one end of the actuator assembly;

FIG. 14 illustrates another perspective view of the actuator assemblyshown in FIG. 12, particularly illustrating the opposite end of theactuator assembly shown in FIG. 13;

FIG. 15 illustrates a top view of the actuator assembly shown in FIG.12, particularly illustrating various internal components and/orfeatures of the actuator assembly in dashed or hidden lines;

FIG. 16 illustrates an exploded view of the actuator assembly shown inFIG. 12;

FIG. 17 illustrates another exploded view of several of the componentsof the actuator assembly shown in FIG. 16;

FIG. 18 illustrates a bottom perspective view of a housing component ofthe actuator assembly shown in FIG. 12, particularly illustratingvarious ports and channels defined in the housing component as well asvarious components of a driver assembly of the actuator assemblypositioned within the housing component;

FIG. 19 illustrates another bottom perspective view of the housingcomponent shown in FIG. 18, particularly illustrating the driverassembly components removed for purposes of illustration;

FIG. 20 illustrates a side view of the activator device shown in FIG.12;

FIG. 21 illustrates a perspective view of activator device shown in FIG.12 with a portion of an outer cover of the activator device removed toallow the various internal components of the activator device to beshown;

FIG. 22 illustrates a cross-sectional view of the actuator assemblyshown in FIG. 15 taken about line 22,23-22,23, particularly illustratingone embodiment of a pressure sensor arrangement for sensing the pressureof the fluid supplied within the system;

FIG. 23 illustrates another cross-sectional view of the actuatorassembly shown in FIG. 15 taken about line 22,23-22,23, particularlyillustrating another embodiment of a pressure sensor arrangement forsensing the pressure of the fluid supplied within the system;

FIG. 24 illustrates a cross-sectional view of another embodiment of afluid-actuated balloon valve suitable for use within the disclosedsystem, particularly illustrating the valve in a closed position andalso illustrating a pressure sensor provided in operative associatedwith the valve;

FIG. 25 illustrates a simplified, perspective view of another embodimentof arteriovenous access valve system in accordance with aspects of thepresent subject matter;

FIG. 26 illustrates a side view one embodiment of an activator devicethat may be utilized on connection with the system shown in FIG. 25; and

FIG. 27 illustrates a schematic view of another embodiment of anactuator assembly that may be utilized in accordance with aspects of thepresent subject matter, particularly illustrating the actuator assemblyincluding various drive options.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

In general, the present subject matter is directed to a magneticallyactivated arteriovenous access valve system. Specifically, in severalembodiments, the system may include a subcutaneously implanted actuatorassembly in fluid communication with fluid actuated valves (e.g.,balloon valves) positioned at each end of an arteriovenous graft. Inaddition, the system may include an external activator device configuredto activate the actuator assembly using magnetic forces. For example, aswill be described below, the activator device may include a motorconfigured to rotate one or more magnets contained within the deviceboth clockwise and counter-clockwise. By placing the activator deviceadjacent to the location of the implanted actuator assembly, rotation ofthe magnet(s) may activate a driver assembly of the actuator assembly(e.g., a screw drive or a gear pump), thereby causing fluid to bedelivered to and/or drawn away from the balloon valves. For instance, byrotating the magnet(s) in a first direction, the driver assembly may beconfigured to supply fluid into the balloons associated with the valvesin order to close the valves and prevent blood from flowing through thegraft. Similarly, by rotating the magnet(s) in the opposite direction,the driver assembly may be configured to draw fluid out of the balloonsin order to open the valves and allow blood to flow through the graft

Additionally, in several embodiments, one or more pressure sensors maybe incorporated into the disclosed system, such as by positioning thepressure sensor(s) within the actuator assembly and/or by associatingthe pressure sensor(s) with the valves and/or the tubing connecting theactuator assembly to the valves. The pressure sensor(s) may generally beconfigured to read the pressure of the fluid contained within the systembetween the driver assembly and the valves, thereby providing anindication of the inflation/deflation level of each balloon. Forinstance, as will be described below, the system may, in one embodiment,include two pressure sensors, with each pressure sensor being configuredto monitor the pressure of the fluid supplied to one of the valves. Assuch, pressure measurements may be obtained that allow for theinflation/deflation level of each balloon valve to be individuallymonitored.

Moreover, as will be described below, the actuator assembly may alsoinclude a sensor communications device for wirelessly transmitting thepressure measurements provided by the pressure sensor(s) to a separatedevice located exterior to the patient. For example, in severalembodiments, the exterior activator device may include an antenna orother suitable components for receiving wireless transmissionsassociated with the fluid pressure within the system. In suchembodiments, the pressure measurements received from the actuatorassembly may then be utilized to provide the operator of the activatordevice with an indication of the inflation/deflation level of theballoon valves. For instance, the activator device may include asuitable indicator means (e.g., an indicator light, a light bar, displaypanel and/or the like) that provides the operator an indication of whenthe balloon valves are fully closed/opened or a condition in which theballoons are partially inflated for the purpose of modulating flow. Assuch, when using the activator device to activate the actuator assembly,the operator may maintain the activator device adjacent to the locationof the implanted actuator assembly (e.g., at a location adjacent toand/or contacting the patient's skin) so as to rotatably drive thedriver assembly until the indicator means provides an indication thatthe balloons are fully inflated or fully deflated, at which point theoperator may turn off the activator device or otherwise move the deviceaway from the location of the actuator assembly. In addition toproviding the operator an indication of the inflation/deflation level ofthe balloon valves)r as an alternative thereto), the pressuremeasurements may also be utilized to automatically control the operationof the activator device. For instance, in one embodiment, the activatordevice may be automatically turned off when it is determined that theballoon valves are fully inflated and/or fully deflated.

Additionally, in several embodiments, the sensor communications deviceprovided within actuator assembly may be configured to be remotelypowered, thereby eliminating the need for a battery to be includedwithin the implanted assembly. For example, as will be described below,the activator device may, in one embodiment, be configured to beutilized as an initiator device for near field communications (NFC) bygenerating a radiofrequency (RF) field that is configured to power thesensor communications device. Thus, when the activator device is placedadjacent to the location of the implanted actuator assembly so as tomagnetically drive the driver assembly, the activator device may alsogenerate a suitable RF field for powering the sensor communicationdevice. As a result, the sensor communications device may wirelesslytransmit pressure measurements to the activator device as the activatordevice is being used to inflate or deflate the valve balloons, therebyproviding the activator device with real-time pressure measurements thatcan then be used to provide a visual indication of when the valveballoons are properly inflated or deflated and/or to automaticallycontrol the operation of the activator device.

It should be appreciated that the disclosed actuator assembly andrelated system may generally provide numerous advantages for performinghemodialysis in patients. For example, the magnetically activated devicemay allow for the valves to be activated using a reusable, hand-heldactivation device. As such, there is no need for additional hypodermicneedles that must be thrown away after use, thereby substantiallyreducing the ongoing costs for performing hemodialysis. In addition, theneedle-free, external activation provided via the disclosed system mayincrease patient comfort. Moreover, the various components of thedisclosed system are relatively inexpensive and easy to manufacture.Further, the ability to wirelessly monitor the pressure within thesystem provides an efficient and effective means for ensuring that thevalves have been properly opened and/or closed during the performance ofthe hemodialysis process.

Referring now to FIG. 1, for purposes of explanation, a right arm 10 ofa patient is shown. Selected arteries (shown as dotted pathways) areillustrated in conjunction with selected veins (shown as dark pathways).An arteriovenous graft 12 is shown connected at one end to an artery andat an opposite end to a vein. In particular, the arteriovenous graft 12is connected to the brachial artery 14 and to the cephalic vein 16.

Referring now to FIG. 2, one embodiment of an arteriovenous access valvesystem 50 is illustrated in accordance with aspects of the presentsubject matter. As shown, the system 50 may include an arteriovenousgraft 12 coupled between an artery 14 and a vein 16. In order to carryout hemodialysis, a first hypodermic needle 18 is inserted through theskin and into the arteriovenous graft 12. Blood is removed from thearteriovenous graft 12 through the needle and into a dialysis machine20. In the dialysis machine, waste materials are removed from the blood.After circulating through the dialysis machine 20, the blood is then fedback into the arteriovenous graft 12 through a second hypodermic needle22.

In addition, the system 50 may include a first valve device 24(hereinafter referred to simply as the first valve 24 or valve 24)positioned at or adjacent to the arterial end of the arteriovenous graft12 and a second valve device 26 (hereinafter referred to simply as thesecond valve 26 or valve 26) positioned at or adjacent to the venous endof the arteriovenous graft. In this regard, one or more components ofthe valves 24, 26 (e.g., a sleeve of the valves 24, 26) may have acomplimentary shape to the artery and/or vein and define holes (notshown) to permit direct suturing between the device(s) and the arteryand/or vein to further reinforce the connection and prevent each valve24, 26 from moving away from its intended location. The valves 24, 26are in an open position during normal hemodialysis as shown in FIG. 2.When hemodialysis has ended, however, the valves 24, 26 are moved to aclosed position in order to prevent blood flow through the arteriovenousgraft 12. In this manner, arterial steal is either eliminated orreduced. Further, by reducing turbulent blood flow through thearteriovenous graft, graft thrombosis is also prevented.

In several embodiments, the valves 24, 26 may correspond toballoon-actuated valves and, thus, may each include an inflatableballoon (not shown). When inflated, the balloons close the valves 24, 26in a manner that reduces or eliminates the blood flow through the graft12. In contrast, when the balloons are deflated, the valves 24, 26 areopened and blood may be directed through the arteriovenous graft 12. Aswill be described in greater detail below, to provide for suchinflation/deflation of the balloons, the first and second valves 24, 26may be in fluid communication with an actuator assembly 100, 200 (e.g.,via tubing). Specifically, as shown in the illustrated embodiment, theactuator assembly 100, 200 may be in fluid communication with the firstvalve device 24 via a first valve tube 40 and may be in fluidcommunication with the second valve device 26 via a second valve tube42.

Referring now to FIGS. 3-9, various views of one embodiment of anactuator assembly 100 suitable for use within the disclosed system 50are illustrated in accordance with aspects of the present subjectmatter. Specifically, FIG. 3 illustrates a perspective view of theactuator assembly 100 and one embodiment of an associated activatordevice 102 that may be used in connection with the actuator assembly 100in accordance with aspects of the present subject matter. FIGS. 4 and 5illustrate additional perspective views of the actuator assembly 100 andthe associated activator device 102, particularly illustratingcomponents of the actuator assembly 100 in an unactuated position (FIG.4) and an actuated position (FIG. 5). FIG. 6 illustrates across-sectional view of the actuator assembly 100 shown in FIGS. 3-5.FIG. 7 illustrates a line drawing of the actuator assembly 100,particularly illustrating various internal components of the actuatorassembly 100 (and also including one or more internal components of theactuator assembly 100 removed for purposes of illustrating features ofother internal components). FIG. 8 illustrates another perspective viewof the actuator assembly 100. Additionally, FIG. 9 illustrates a sideview of the activator device 102. It should be appreciated that in someor all of FIGS. 3-8, various exterior surfaces and/or walls of theactuator assembly 100 have been illustrated as fully or semi-transparent(e.g., via the dashed lines) to allow for the various internalcomponents of the assembly 100 to be shown in the drawings for purposesof describing the present subject matter.

As shown in the illustrated embodiment, the actuator assembly 100 maygenerally include a housing 104 configured to serve as an outer casingor shell for the various internal components of the assembly 100. Asindicated above, the actuator assembly 100 may be configured to besubcutaneously implanted within a patient, such as in the patient's armor leg. As such, it should be appreciated that the housing 104 maygenerally be made from any suitable biocompatible material, such as asuitable rigid biocompatible material (e.g., titanium).

In general, the housing 104 may be configured to extend lengthwisebetween a first end 106 and a second end 108. As shown in theillustrated embodiment, a driver assembly 110 of the actuator assembly100 may be associated with and/or housed within the housing 104 at oradjacent to its first end 106. As will be described below, the driverassembly 110, when activated, may be configured to drive a plunger 112forward and backwards in the directions indicated by arrows 114 shown inFIG. 3, thereby allowing a suitable fluid (e.g., a saline solution) tobe both discharged from and aspirated back into a fluid chamber 116defined within the housing 104. Additionally, as shown in theillustrated embodiment, the actuator assembly 100 may include a firstoutlet port 118 and a second outlet port 120 extending from and/ordefined through the second end 108 of the housing 104. As will bedescribed below, the outlet ports 118, 120 may be in fluid communicationwith both the fluid chamber 116 and the valves 24, 26 (e.g., via valvetubes 40, 42). Thus, as the fluid is discharged from the fluid chamber116 by moving the plunger 112 in the direction of the outlet ports 118,120, the fluid may he directed through the ports 118, 120 and into thecorresponding valves 24, 26 in order to close each valve 24, 26 (e.g.,by inflating the associated balloons). Similarly, to open the valves 24,26, the plunger 112 may be moved in the opposite direction to aspiratethe fluid back into the fluid chamber 116.

It should be appreciated that, in several embodiments, the housing 104may be configured to be formed from a plurality of different housingcomponents. In such embodiments, the various housing components may beconfigured to be coupled together using any suitable attachment meansknown in the art, as mechanical fasteners, brackets, threadedcomponents, sealing mechanisms, adhesives and/or the like and/or usingany suitable attachment process known in the art, such as welding (e.g.,laser welding).

In several embodiments, the driver assembly 110 may include a rotatabledriver 122 configured to linearly actuate a threaded member 124 (e.g., ascrew) coupled to the plunger 112. For example, as shown in theillustrated embodiment, the rotatable driver 122 may correspond to arotatable driver disc 122 positioned within the housing 104 adjacent toan outer face 126 of the housing 104 defined at or adjacent to its firstend 106. The driver disc 122 may, in turn, be coupled to the threadedmember 124 via one or more intermediate driver members 128, 130 suchthat rotation of the disc 122 results in linear translation of thethreaded member 124. For instance, as particularly shown in FIG. 6, thedriver disc 122 may include a driver wheel or gear 128 formed integrallytherewith or coupled thereto such that the driver gear 128 rotates withrotation of the disc 122. Additionally, as shown in FIG. 6, the drivergear 128 may, in turn, be rotatably coupled to a linear driver 130defining a threaded opening 132 configured to receive the threadedmember 124. For example, in a particular embodiment, a plurality of gearteeth 134 (FIG. 7) may be defined around an end surface 136 (FIG. 6) ofthe linear driver 130 that are configured to rotationally engage thecorresponding gear teeth of the driver gear 128. As such, as the drivergear 128 is rotated with the rotatable disc 122, the rotationalengagement between the driver gear 128 and the linear driver 130 mayallow for rotation of the linear driver 130 about a longitudinal axis138 (FIG. 6) of the threaded member 124.

Moreover, given the threaded engagement defined between the threadedopening 132 of the linear driver 130 and the threaded member 124,rotation of the linear driver 130 about the longitudinal axis 138 of thethreaded member 124 may cause the threaded member 124 and, thus, theplunger 112 coupled thereto to be translated linearly within the fluidchamber 116 between an unactuated position (FIGS. 4 and 6) and anactuated position (FIGS. 3, 5 and 7). Such linear translation of theplunger 112 within the fluid chamber 116 may allow for the fluid to bedischarged from and drawn back into the chamber 116 when opening andclosing the valves 24, 26, respectively.

For example, referring particularly to FIG. 6, when the plunger 112 islocated in the unactuated position, a significant portion of the fluidused to actuate the valves 24, 26 may be contained within the fluidchamber 116. By rotating the rotatable driver 122 in a first direction(e.g., in a clockwise direction), the plunger 112 may be moved from theunactuated position (as shown in FIG. 6) to the actuated position (e.g.,as shown in FIG. 5), thereby pushing or forcing the fluid out of thefluid chamber 116. As a result, the fluid may be directed through theoutlet ports 118, 120 and into the valves 24, 26 (e.g., via valve tubes40, 42) in order to inflate the associated balloons and, thus, move thevalves 24, 26 to the closed position. Thereafter, in order to open thevalves 24, 26, the rotatable driver 122 may be rotated in the oppositedirection (e.g., in a counter-clockwise direction), which may cause theplunger 112 to be moved from the actuated position back to theunactuated position. Such movement of the plunger 112 may generallyresult in the fluid being drawn back into the fluid Chamber 116, therebydeflating the balloons and opening the valves 24, 26.

It should be appreciated that, given the disclosed configuration, theplunger 112 may operate similar to the plunger included within a needleor syringe. For instance, a seal may be created at the interface definedbetween the outer perimeter of the plunger 112 and the inner walls ofthe fluid chamber 116. Thus, as the plunger 112 is moved to the actuatedposition, it may effectively push the fluid out of the chamber 116.Similarly, a vacuum may be created within the fluid chamber 116 as theplunger 112 is retracted to the unactuated position that causes thefluid to be drawn from the balloons and back into the chamber 116.

In accordance with several aspects of the present subject matter, thedriver assembly 110 may be configured to be activated or drivenmagnetically using the disclosed activator device 102. Specifically, inseveral embodiments, the rotatable driver disc 122 may be configured tobe rotatably driven by one or more rotating magnets contained within theactivator device 102. Thus, by placing the activator device 102 adjacentto the location of the driver assembly 110, the activator device 102 maybe used to externally drive the driver assembly 110, thereby allowingthe valves 24, 26 to be easily and effectively opened and closed. Forinstance, in one embodiment, the activator device 102 may be placed incontact with or adjacent to the patient's skin at a location directlyabove the location of the driver assembly 110, such as adjacent to asuitable recess formed within the housing 104 along the outer face 126(e.g., as shown in FIGS. 3 and 8), to allow the driver assembly 110 tobe magnetically driven.

In general, the activator device 102 may correspond to a small,hand-held device. As particularly shown in FIGS. 7 and 9, in severalembodiments, the activator device 102 may include a reversible motor 140rotatably coupled to one or more activator magnets 142 positioned atand/or adjacent to a contact end 144 of the device 102. The activatormagnet(s) 142 may, in turn, be configured to magnetically react with allor a portion of the rotatable driver disk 122. For example, as shown inFIGS. 4 and 5, the driver disc 122 may include one or more disc magnets146 incorporated therein and/or coupled thereto for reacting with theactivator magnet(s) 142. In such an embodiment, due to the magneticforces between the activator magnet(s) 142 and the disc magnet(s) 146,rotation of the activator magnet(s) 142 may result in rotation of thedriver disc 122, thereby linearly actuating the plunger 112 and causingthe fluid to be discharged from or drawn into the fluid chamber 116.

It should be appreciated that the reversible motor 140 may be configuredto rotate the activator magnet(s) 142 in both a clockwise and acounter-clockwise direction. Thus, by rotating the motor 140 in a firstdirection, the driver disc 122 may be rotated in a direction that causesthe plunger 112 to be moved to the actuated position. Similarly, byrotating the motor 140 in the opposite direction, the driver disc 122may be rotated in the appropriate direction for moving the plunger 112to the unactuated position. As shown in FIG. 9, in one embodiment, theactivator device 102 may include suitable user control buttons 148, 150to allow the operator to select the desired rotational direction of themotor 140. For instance, a first button 148 may be provided for rotatingthe motor 140 in the direction that causes the plunger 112 to be movedto the actuated position, thereby closing the valves 24, 26. Similarly,a second button 150 may be provided for rotating the motor in theopposite direction, thereby moving the plunger 112 to the unactuatedposition and opening the valves 24, 26.

It should be appreciated that that the activator device 102 may alsoinclude various other components and/or features. For instance, in oneembodiment, activator device 102 may include all or a portion of thevarious components and/or features of the activator device 202 describedbelow with reference to FIGS. 12, 20 and 21.

Referring still FIGS. 3-9, in several embodiments, the actuator assembly100 may also include a back-up septum 152 that provide a means foradding fluid into and/or removing fluid from the actuator assembly 100to ensure that the proper amount of fluid is contained within theassembly 100 and/or to open/close the valves 24, 26. For example, asshown in the illustrated embodiment, the septum 152 may be located on anouter face 154 of the housing 104 generally defined between the outletports 118, 120 and the fluid chamber 116. Thus, if necessary, ahypodermic needle may be inserted into the patient's skin and throughthe septum 152 to add and/or remove fluid from the actuator assembly100. For instance, if the driver assembly 110 is not operating properly,fluid may be removed from the actuator assembly 100 via the septum 152in order to open the valves 24, 26. Similarly, additional fluid may beadded to the actuator assembly 100 via the septum 152 in order to closethe valves 24, 26.

It should be appreciated that the septum 152 may be made from anysuitable material capable of receiving the tip of a hypodermic needle.For example, in one embodiment, the septum 152 may be made from anelastomeric film, such as a silicone membrane.

It should also be appreciated that, in several embodiments, the actuatorassembly 100 may also include a pressure accumulator 156 disposed withinthe housing 104. For example, as shown in FIG. 8, in one embodiment, thepressure accumulator 156 may be disposed within the housing 104 directlybelow the septum 152. As should be readily appreciated, the pressureaccumulator 156 may be configured to assist in maintaining a constantpressure of the fluid contained within the system.

Additionally, in several embodiments, the disclosed system 50 mayinclude a suitable means for sequentially closing the valves 24, 26.Specifically, in one embodiment, it may be desirable to close the valvepositioned at the arterial end of the arteriovenous graft 12 (e.g., thefirst valve device 24) prior to closing the valve positioned at thevenous end of the graft 12 (e.g., the second valve device 26). Forexample, by delaying the closing of the valve positioned at the venousend of the graft 12 by a given period of time, it may allow for anyblood contained within the graft 12 to be flushed out (e.g., byinjecting a blood compatible fluid into the graft 12 using, for example,a dialysis needle). Thereafter, such valve may then be closed to preventblood from flowing back into the graft 12 from the vein.

In several embodiments, the sequential closing of the valves 24, 26 maybe achieved by varying the inner diameter of the outlet ports 118, 120of the actuator assembly 100. For instance, in a particular embodiment,the inner diameter of the outlet port in fluid communication with thevalve positioned at the arterial end of the graft 12 may be larger thanthe inner diameter of the outlet port in fluid communication with thevalve positioned at the venous end of the graft 12. As such, fluidcontained within the fluid chamber 116 may be initially encouraged toflow in the direction of the valve positioned at the arterial end of thegraft 12, thereby allowing such valve to be closed first. It should beappreciated that, in general, the inner diameters of the outlet ports118, 120 may be configured to define suitable size differential thatallows such valves to be sequentially closed in the manner consistentwith the disclosure provided herein. For instance, in a particularembodiment, the inner diameter of the outlet port in fluid communicationwith the valve positioned at the venous end of the graft 12 may besmaller than the inner diameter of the outlet port in fluidcommunication with the valve positioned at the arterial end of the graft12 by at least 5%, such as at least 25% or at least 50% or at least 75%or at least 90%.

In addition to varying the inner diameters of the outlet ports 118, 120or as alternative thereto, the length and/or the inner diameter of thevalve tubes 40, 42 connecting the ports 118, 120 to the valves 24, 26may be varied in order to allow for the valves 24, 26 to be sequentiallyclosed. For instance, the valve tube connecting the valve positioned atthe venous end of the graft 12 to its corresponding outlet port may belonger than and/or define a smaller diameter than the valve tubeconnecting the valve positioned at the arterial end of the graft 12 toits corresponding outlet port to allow the valve positioned at thearterial end of the graft 12 to be closed first.

It should be appreciated that, in alternative embodiments, the actuatorassembly 100 and/or any other related components of the system 50 may beconfigured such that the valves 24, 26 are simultaneously opened andclosed.

It should also be appreciated that the actuator assembly 100 and/orsystem 50 shown in FIGS. 3-8 may additionally include various othercomponents and/or features. For instance, in one embodiment, actuatorassembly 100 and/or system 50 may include all or a portion of thevarious components and/or features of the actuator assembly 200 and/orsystem 50 described below with reference to FIGS. 12-25.

Additionally, it should be appreciated that the valves 24, 26 describedherein may generally correspond to any suitable fluid-actuated valvesknown in the art. For example, as indicated above, in severalembodiments, the valves 24, 26 may correspond to fluid-actuated balloonvalves. In such embodiments, the balloon valves may generally have anysuitable configuration known in the art for closing and opening thevalves 24, 26 by inflating and deflating the balloons, respectively,using any suitable fluid. For instance, one embodiment, each balloon maybe annular-shaped and may be configured to wrap circumferentially aroundthe graft 12 such that, when inflated, the balloons extend radiallyinwardly and prevent blood from flowing through the graft. Such balloonsare described, for example, in U.S. Pat. No. 7,025,741, which is herebyincorporated by reference herein in its entirety for all purposes.

In another embodiment, the balloons may be configured to be disposedin-line with the graft 12 (or in-line with any suitable coupling influid communication with the graft 12, such as one or more sleevespositioned within the graft 12 or coupled to the graft 12 at its ends).For instance, FIGS. 10 and 11 illustrate one example of a suitablein-line balloon valve 24, 26 that may be utilized within the disclosedsystem 50 in accordance with aspects of the present subject matter.Specifically, FIG. 10 illustrates the valve 24, 26 in a closed positionand FIG. 11 illustrates the valve 24, 26 in an opened position.

As shown, the valve 24, 26 may include a cylindrical housing or sleeve174 extending between a first end 176 and a second end 178, with thefirst end 176 of the sleeve 174 being configured to be coupled to acorresponding end of the arteriovenous graft 12 (e.g., the arterial endor the venous end of the graft 12) using any suitable attachment means(e.g., sutures (not shown)) and the second end 178 of the sleeve 174being configured to be coupled to either an artery 14 or a vein 16 ofthe patient using any suitable attachment means (e.g., sutures).Alternatively, the sleeve 174 may be configured as an integral portionof the graft 12 such that the second end 178 of the sleeve 172corresponds to the arterial or venous end of the graft 12.

Additionally, the valve 24, 26 includes a balloon 180 configured to bepositioned at least partially in-line with the sleeve 174. For example,in several embodiments, the sleeve 174 may include a raised portion 182configured to extend radially outwardly relative to the remainder of thesleeve 174 such that a recess 184 is defined directly below the raisedportion 182 for receiving both the balloon 180 and the tubing 40, 42extending between the balloon 180 and the actuator assembly 100. Assuch, when the balloon 180 is deflated (as shown in FIG. 11), theballoon 180 may be retracted back into the recess 184 so that theballoon provides no or minimal restriction to the flow of blood throughthe graft/sleeve 12, 174. For example, as shown in FIG. 11, in oneembodiment, the balloon 180 may be configured to be retracted back intothe recess 184 such that the inner surface of the balloon 180 isgenerally aligned within an inner surface 186 of the sleeve 174 and/orthe graft 12. Additionally, as shown in FIG. 10, when fluid is suppliedto the balloon 180 so as to close the valve 24, 26, the balloon may beconfigured to expand outwardly from the recess 184 into the interior ofthe sleeve 174 such that the balloon 180 completely blocks the flow ofblood through the sleeve 174.

Referring now to FIGS. 12-21, various views of another embodiment of anactuator assembly 200 suitable for use within the disclosed system 50are illustrated in accordance with aspects of the present subjectmatter. Specifically, FIG. 12 illustrates a perspective view of theactuator assembly 200 and one embodiment of an associated activatordevice 202 that may be used in connection with the actuator assembly 200in accordance with aspects of the present subject matter. In addition,FIG. 12 also illustrates various other system components that may beutilized in connection with the actuator assembly 200 in accordance withaspects of the present subject matter. FIGS. 13 and 14 illustrateperspective views of opposed first and second ends, respectively, of theactuator assembly 200 shown in FIG. 12 (with the tubing shown in FIG. 12being removed) and FIG. 15 illustrates a top view of the actuatorassembly 200 shown in FIGS. 13 and 14. FIG. 16 illustrates an explodedview of the actuator assembly 200 shown in FIGS. 13-15 and FIG. 17illustrates an exploded view of various components of the actuatorassembly 200 shown in FIG. 16. FIGS. 18 and 19 illustrate differingperspective, bottom views of a housing component of the actuatorassembly 200, with FIG. 18 illustrating the housing component withsuitable gears installed therein and FIG. 19 illustrating the housingcomponent with the gears removed. Additionally, FIG. 20 illustrates afront view of the activator device 202 shown in FIG. 12 and FIG. 21illustrates a perspective view of the activator device 202 shown in FIG.20 with at least a portion of an outer casing or shell of the device 202being removed so as to illustrate various internal components of theactivator device 202.

As shown in the illustrated embodiment, the actuator assembly 200 maygenerally include a housing 204 configured to serve as an outer casingor shell for the various internal components of the assembly 200. Asindicated above, the actuator assembly 200 may be configured to besubcutaneously implanted within a patient, such as in the patient's armor leg. As such, it should be appreciated that the housing 204 maygenerally be made from any suitable biocompatible material, such as a.suitable rigid biocompatible material (e.g., titanium).

In general, the housing 204 may be configured to extend lengthwisebetween a first end 206 and a second end 208. As shown in theillustrated embodiment (e.g., in FIGS. 16 and 17), amagnetically-activated driver assembly 210 of the actuator assembly 200may be associated with and/or housed within the housing 204 between itsfirst and second ends 206, 208. As will be described below, the driverassembly 210, when activated, may be configured to pump or transport asuitable fluid (e.g., a saline solution) between a fluid chamber orreservoir 212 positioned exterior to the housing 204 and the valves 24,26 fluidly connected to the actuator assembly 200 via the valve tubes40, 42. Additionally, as shown in the illustrated embodiment, theactuator assembly 200 may include an inlet port 214 defined by and/orthrough a portion of the housing 204 (e.g., at the first end 206 of thehousing 204) and first and second outlet ports 216, 218 defined byand/or through a different portion of the housing 204 (e.g., at thesecond end 208 of the housing 204). As will be described below, theinlet port 214 may be in fluid communication with the fluid reservoir212 (e.g., via a suitable reservoir tube 220). Similarly, the first andsecond outlet ports 216, 218 may be in fluid communication with thefirst and second valves 24, 26, respectively (e.g., via the valve tubes40, 42). Thus, as fluid is pumped from the fluid reservoir 212 into thehousing 204 due to activation of the driver assembly 210, the fluid maybe expelled from the housing 204 via the outlet ports 216, 218 and intothe corresponding valves 24, 26 in order to close each valve 24, 26(e.g., by inflating the associated balloons). Similarly, to open thevalves 24, 26, the driver assembly 210 may be rotatably driven in theopposite direction to draw the fluid out of the balloons and direct itback through the housing 204 and into the fluid reservoir 212.

It should be appreciated that, in several embodiments, the housing 204may be configured to be formed from a plurality of different housingcomponents. For example, as shown in FIGS. 13, 14 and 16, the housing204 may be formed from an upper housing component 222, a lower housingcomponent 224 and a central housing component. 226. In such embodiments,the various housing components 222, 224, 226 may be configured to becoupled together using any suitable attachment means known in the art,such as mechanical fasteners, brackets, threaded components, sealingmechanisms, adhesives and/or the like, and/or using any suitableattachment process known in the art, such as welding (e.g., laserwelding).

In several embodiments, the central housing component 226 may beconfigured to define a flow path for the fluid being directed throughthe housing 204 between the inlet port 214 and the outlet ports 216,218. For example, as shown in FIGS. 18 and 19, the central housingcomponent may define an inlet flow channel 228 extending between theinlet port 214 and a gear pump of the drive assembly 210 (describedbelow) and an outlet flow channel 230 extending between the gear pumpand the outlet ports 216, 218. As such, when fluid is being directedthrough the housing 204 from the fluid reservoir 212 to the valves 24,26, the fluid entering the housing 204 via the inlet port 214 may bedirected into inlet flow channel 228 and through the gear pump.Thereafter, the fluid may flow through the outlet flow channel 230 andmay then be expelled from the housing 204 via the outlet ports 216, 218.

Additionally, as shown in FIG. 12, the fluid reservoir 212 may generallycorrespond to a separate component configured to be fluidly coupled tothe actuator assembly 200 via the reservoir tube 220. By providing sucha separate fluid reservoir 212, the overall size of the actuatorassembly 200 may be reduced significantly as compared to a configurationin which the fluid needed to actuate the valve devices 24, 26 is storedentirely within the actuator assembly 200. It should he appreciated thatthe fluid reservoir 212 may generally be formed from a pliable orflexible polymer material so as to allow the reservoir 212 to bepositioned adjacent to the implant location of the actuator assembly 200with minimal or no added discomfort to the patient.

It should also be appreciated that, in alternative embodiments, theactuator assembly 200 may, instead, include a fluid reservoir or chamberdefined within the housing 200. Specifically, similar to the fluidchamber 116 described above with reference to FIGS. 3-9, an internalcavity may be defined within the housing 204 for containing the fluid tobe supplied to the valves 24, 26. For instance, as shown in dashed linesin FIG. 19, the central housing component 226 may define an internalcavity 232 for storing fluid therein. In such instance, the system 50need not include the separate reservoir 212 and the actuator assembly200 need not include the inlet port 214 since fluid may be supplieddirectly from the internal cavity 232 to the valves 24, 26.

As particularly shown in FIGS. 16-18, in several embodiments, the driverassembly 210 may include two separate gears 234, 236 (e.g., spur gears)configured to function as a gear pump for pumping fluid between thefluid reservoir 212 and the valves 24, 26. Specifically, as shown in theillustrated embodiment, the driver assembly 210 includes a drive gear234 and an idler gear 236, with each gear 234, 236 being configured tobe positioned within a corresponding gear cavity 238 (FIGS. 18 and 19)defined by the central housing component 226. The drive gear 234 may beconfigured to be rotatably coupled to a corresponding drive shaft 240 ofthe driver assembly 210. Additionally, the idler gear 236 may beconfigured to be rotatably supported within its gear cavity 238 via agear post 242 (FIG. 19) extending into the cavity 238 from the centralhousing component 226. In general, the gears 234, 236 may be configuredto mesh with or engage one another such that, as the drive gear 234 isrotated via rotation of the drive shaft 238, the idler gear 236 may berotated about the gear post 242. Such meshing or engagement of the gears234, 236 may generally result in the positive displacement of fluidthrough the gear pump. Thus, by rotating the gears 234, 236 in a firstdirection, the gear pump may be configured to pump fluid from thereservoir 212 in the direction of the valves 24, 26. Similarly, byrotating the gears 234, 236 in the opposite direction, the gear pump maybe configured to pump fluid from the valves 24, 26 back in the directionof the fluid reservoir 212.

An example flow path for the fluid being pumped through the housing 204between the inlet port 214 and the outlet ports 216, 218 is illustratedby the arrows provided in FIG. 18. As shown, by rotating the gears 234,236, fluid may be pumped into the housing 204 via the inlet port 214 andflow through the inlet flow channel 228 to the gear pump. The fluid maythen be directed along two separate flow paths defined between the outerperimeter of each gear 234, 236 and the inner perimeter of itscorresponding gear cavity 238 before flowing into the outlet flowchannel 230. As shown in FIG. 18, flow diverters 244 may be provided oneach side of the gear pump to facilitate diverting the flow of fluidinto the two separate flow paths. The fluid flowing into the outlet flowchannel 230 may then be directed into the outlet ports 216, 218 andexpelled from the housing 204.

In accordance with several aspects of the present subject matter, thedriver assembly 210 may be configured to be activated or drivenmagnetically using the disclosed activator device 202. Specifically, inseveral embodiments, the drive shaft 240 may be configured to berotatably driven by one or more drive magnets 246 positioned within thehousing 204 adjacent to its outer face 248 (e.g., the outer face 248defined by the upper housing component 222). For example, as shown inFIGS. 16 and 17, a disc-shaped drive magnet 246 may be configured to bepositioned within a magnet cup 250 provided within the housing 204 sothat the drive magnet 246 and the magnet cup 250 are rotatably engagedwith one another. In such an embodiment, the drive shaft 240 may beformed integrally with and/or may be coupled to the magnet cup 250 andextend outwardly therefrom so as to be rotatably coupled to the drivegear 234. For instance, as shown in FIG. 17, the drive shaft 240 may beconfigured to extend through an opening 252 defined in an upper wall ofthe central housing component 226 to allow the drive shaft 240 to berotatably coupled to the drive gear 234. As a result, rotation of boththe drive magnet 246 and its corresponding magnet cup 250 mayrotationally drive the drive shaft 240, which, in turn, results inrotation of the drive gear 234. Thus, by placing the activator device202 adjacent to the location of the driver assembly 210, the activatordevice 202 may be used to externally drive the driver assembly 210,thereby allowing the valves 24, 26 to be easily and effectively openedand dosed. For instance, in one embodiment, the activator device 202 maybe placed in contact with or adjacent to the patient's skin at alocation directly above the outer face 248 of the housing 204 to allowthe driver assembly 210 to be magnetically driven.

It should be appreciated that, in several embodiments, the actuatorassembly′ 200 may also include one or more suitable bearings or bearingelements to facilitate or enhance rotation of the magnet cup 250 withinthe housing 204. For instance, as shown in FIG. 16, an annular assemblyof balls 254 may be configured to be positioned between the magnet cup250 and the housing 204 (e.g., at the location of the upper housingcomponent 222). In such an embodiment, the balls 254 may be verticallysupported within the housing 204 via an annular flange 256 (FIGS. 16 and17) extending outwardly from the magnet cup 250.

Referring particularly to FIGS. 12, 20 and 21, the activator device 202may generally be configured similar to the activator device 102described above. Specifically, in several embodiments, the activatordevice 202 may correspond to a small, hand-held device that includes areversible motor 258 rotatably coupled to one or more activator magnets260 positioned at and/or adjacent to a contact end 262 of the device202. The activator magnet(s) 260 may, in turn, be configured tomagnetically react with the drive magnet 246 provided within the housing204, thereby allowing the gear pump to be magnetically driven in mannerthat allows fluid to be pumped out of and back into the fluid reservoir212. Similar to the embodiment described above, it should be appreciatedthat the reversible motor 258 may be configured to rotate the activatormagnet(s) 260 in both a clockwise and a counter-clockwise direction.Thus, by rotating the motor 258 in a first direction, the drive magnet246 may be rotated in a direction that causes the drive and idler gears234, 236 of the driver assembly 210 to be rotated in a correspondingdirection for pumping fluid from the reservoir 212 to the valves 24, 26.Similarly, by rotating the motor 258 in the opposite direction, thedrive magnet 246 may be rotated in a direction that causes the gears234, 236 to be rotated in a corresponding direction for pumping fluidfrom the valves 24, 26 back into the reservoir 212.

In several embodiments, the activator device 202 may include one or moreuser interface elements to allow the operator to select the desiredrotational direction of the motor 258. For instance, as shown in FIG.20, a toggle switch 264 may be provided on the exterior of the activatordevice 202 that can be toggled from a neutral or off position (e.g., theposition at which the motor 258 is turned off) to a forward or“inflation” position so as to cause the motor 258 to be rotated in afirst direction and from the off position to a reverse or “deflation”position so as to cause the motor 258 to be rotated in the oppositedirection. In addition, the activator device 202 may also include anindicator light 266 that is configured to be illuminated when the toggleswitch 264 is moved from the off position to the inflation or deflationposition, thereby providing an indication to the operator that the motor258 is rotating. In such an embodiment, the indicator light 266 may, forexample, be configured to be illuminated in different colors to indicatewhether the motor 258 is rotated in the forward or reverse direction.For instance, the indicator light 266 may be illuminated in a greencolor when the motor 258 is being rotated in the forward direction andin a red color when the motor 258 is being rotated in the reversedirection. Alternatively, the activator device 202 may include multipleindicator lights for indicating the operational direction of the motor258. For instance, in a particular embodiment, the activator device 202may include a first indicator light for indicating that the motor 258 isrotating in the forward direction and a second indicator light forindicating that the motor 258 is rotating in the reverse direction.

It should be appreciated that, as an alternative to the toggle switch264, the activator device 202 may include any other suitable userinterface elements that allow the operator to select the desiredrotational direction of the motor 258. For instance, similar to theembodiment described above with reference to FIG. 9, the activatordevice 202 may include separate buttons for rotating the motor 258 inthe forward and reverse directions. Additionally, it should beappreciated that, as an alternative to the indicator light(s) 266, theactivator device 202 may include any other suitable indicator or outputmeans for indicating that the motor 258 is operating and/or forindicating the rotational direction of the motor 258. For example, inalternative embodiment, the activator device 202 may include a suitabledisplay (e.g., an LCD display panel) for displaying a visual indicatorassociated with the operational status of the motor 258.

Referring particularly to FIG. 21, the activator device 202 may alsoinclude various internal components for facilitating operation of thedevice 202. For instance, as shown in FIG. 21, the activator device 202may include a battery 268 for providing power to the various othercomponents of the device 202. In several embodiments, the battery 268may correspond to a rechargeable battery. In such embodiments, theactivator device 202 may be configured to be placed within a suitablecharging station and/or connected to a suitable power cord forrecharging the battery 268.

Additionally, the activator device 202 may include a controller 270 forcontrolling the operation of the various other components of the device202. In general, the controller 270 may correspond to any suitableprocessing unit known in the art. As such, the controller 270 mayinclude, for example, a circuit board 276 providing one or moreprocessors 272 and associated memory 274. As used herein, the term“processor” refers not only to integrated circuits referred to in theart as being included in a computer, but also refers to a controller, amicrocontroller, a microcomputer, a programmable logic controller (PLC),an application specific integrated circuit, and other programmablecircuits. Additionally, the memory 274 of the controller 270 maygenerally comprise a memory element(s) including, but not limited to,computer readable medium (e.g., random access memory (RAM)), computerreadable non-volatile medium (e.g., a flash memory) and/or othersuitable memory elements. Such memory 274 may generally be configured tostore suitable computer-readable instructions that, when implemented bythe processor(s) 272, configure the controller 270 to perform variouscomputer-implemented functions, such as receiving operator inputs (e.g.,via the toggle switch 264), controlling the operation of the motor 258,illuminating the indicator light(s) 266 and/or the like.

Moreover, in several embodiments, the activator device 202 may alsoinclude a wireless communications device 278 for transmitting to and/orreceiving wireless communications from one or more components of theactuator assembly 200. For example, in one embodiment, the wirelesscommunications device 278 may include a suitable processor 280 (e.g., anintegrated circuit) and an associated antenna 282 for transmittingand/or receiving wireless communications. In such an embodiment, theprocessor 280 may correspond to a processor 272 of the controller 170 ora separate processor contained within the activator device 202 (e.g., ona separate circuit board). Alternatively, the wireless communicationsdevice 278 may include any other suitable component(s) that allowswireless communications to be transmitted from and/or received by theactivator device 202.

In a particular embodiment of the present subject matter, the wirelesscommunications device 278 may be configured to serve as an initiatordevice for near field communications (NFC) by actively generating aradiofrequency (RIF) field designed to power a correspondingcommunications device 284 (FIG. 15) provided within the actuatorassembly 200. As will be described below, the NFC-powered communicationsdevice 284 of the actuator assembly 200 may be configured to receivesensor measurements corresponding to the pressure of the fluid containedwithin the system 50 and transmit such sensor measurements back to thewireless communications device 278 installed within the activator device202. The sensor measurements received by the wireless communicationsdevice 278 may then be stored within the associated memory 274 of thecontroller 270 and/or wirelessly transmitted to a separate device incommunication with the activator device 202. In addition, the sensormeasurements may also be utilized to indicate to the operator whetherthe system 50 is operating properly. For instance, as will be describedbelow, the activator device 202 may include an indicator bar 285 orother suitable output device for providing the operator with a visualindication of the inflation/deflation level of the valves 24, 26 basedon the pressure measurements received by the wireless communicationsdevice 278.

Referring still FIGS. 12-21, in several embodiments, the actuatorassembly 200 may also include a back-up septum 286 to provides a meansfor adding fluid into and/or removing fluid from the actuator assembly200 to ensure that the proper amount of fluid is contained within theassembly 200 and/or to open/close the valves 24, 26. For example, asshown in the illustrated embodiment, the septum 286 may be positioned onthe exterior of the housing 204 at a suitable location for providingaccess to the fluid path defined through the housing 204 (e.g., at alocation adjacent to the first end 206 of the housing 204). Thus, ifnecessary, a hypodermic needle may be inserted into the patient's skinand through the septum 286 to add fluid to and/or remove fluid from theactuator assembly 200. For instance, if the driver assembly 210 is notoperating properly, fluid may be removed from the actuator assembly 200via the septum 286 in order to open the valves 24, 26. Similarly,additional fluid may be added to the actuator assembly 200 via theseptum 286 in order to close the valves 24, 26.

It should be appreciated that, similar to the embodiment described abovewith reference to FIGS. 3-8, the septum 286 may be made from anysuitable material capable of receiving the tip of a hypodermic needle.For example, in one embodiment, the septum 286 may be made from anelastomeric film, such as a silicone membrane.

Additionally, in several embodiments, the disclosed system 50 may alsoinclude a pressure accumulator 287 configured to assist in maintaining aconstant pressure of the fluid contained within the system 50. Forexample, as shown in FIG. 12, in one embodiment, the pressureaccumulator 287 may be provided in fluid communication with one of thevalve tubes 40, 42 extending between the actuator assembly 200 and itscorresponding valve 24, 26. In such an embodiment, in addition toassisting in maintaining a constant fluid pressure, the pressureaccumulator 287 may also be configured to serve as a flow restrictor forthe fluid being supplied through the associated valve tube 40, 42. As aresult, the pressure accumulator 287 may provide a means forsequentially closing the valves 24, 26. For instance, as indicatedabove, it may be desirable to close the valve positioned at the arterialend of the arteriovenous graft 12 prior to closing the valve positionedat the venous end of the graft 12. In such instance, the pressureaccumulator 287 may be provided in fluid communication with the valvetube configured to supply fluid to the valve positioned at the venousend of the graft 12, thereby allowing the accumulator 287 to restrictthe flow of fluid to such valve. As a result, the closing of the valvepositioned at the venous end of the graft 12 may be delayed by a timeconstant that is directly proportional to the flow restriction providedby the pressure accumulator 287 so that the valve positioned at thearterial end of the arteriovenous graft 12 is closed first.

It should be appreciated that, in alternative embodiments, the pressureaccumulator 287 may be provided at any other suitable location, such aswithin the housing 204. Moreover, it should be appreciated that, inalternative embodiments, the system 50 may include any other suitablemeans for sequentially closing the valves 24, 26, such as by varying theinner diameter(s) of the outlet ports 216, 218 and/or the tubes 40, 42connecting the outlet ports 216, 218 to the valves 24, 26.

Moreover, in accordance with aspects of the present subject matter, thedisclosed system 50 may also include one or more pressure sensors 288,289 for sensing the pressure of the fluid supplied within the system 50.For example, as particularly shown in FIG. 15, in one embodiment, theactuator assembly 200 may include two pressure sensors (e.g., a firstpressure sensor 288 and a second pressure sensor 289) positioned withinthe housing 204 for monitoring the pressure of the fluid suppliedthrough the housing 204. Specifically, the first pressure sensor 288 maybe provided in fluid communication with the first outlet port 216 formonitoring the pressure of the fluid supplied through such port 216 whenopening and closing the first valve 24. Similarly, the second pressuresensor 289 may be provided in fluid communication with the second outletport 218 for monitoring the pressure of the fluid supplied through suchport 218 when opening and closing the second valve 26. As indicatedabove, by monitoring the pressure of the fluid supplied to each valve24, 26, the operator may be provided an indication of whether theassociated balloons have been fully inflated/deflated as fluid is beingpumped to or drawn out of each valve 24, 26, thereby allowing theoperator to determine if each valve 24, 26 has been properlyclosed/opened.

It should be appreciated that each pressure sensor 288, 289 maygenerally correspond to any suitable sensor(s) configured to directly orindirectly sense the fluid pressure within the system 50. For example,in several embodiments, each pressure sensor 288, 289 may correspond toa pressure-sensitive film configured to provide an output signal(s)(e.g., a current signal(s)) indicative of the load experienced by thefilm due to the pressure of the fluid flowing around and/or past thesensor 288, 289. One example of a suitable pressure-sensitive film thatmay be utilized as a pressure sensor in accordance with aspects of thepresent subject matter is described in U.S. Patent Publication Number2013/0204157 entitled “Contact Sensors, Force/Pressure Sensors andMethods for Making Same” (Clark et al) and filed on Oct. 5, 2012 (U.S.Ser. No. 13/636,345, also published as WO 2011/127306), the disclosureof which is hereby incorporated by reference herein in its entirety forall purposes.

In one particular embodiment of the present subject matter, the pressuresensors 288, 289 may correspond to a pressure sensitive film(s) thatincludes a partially conductive sensor material and at least oneconductor encapsulated within a hermetic/moisture proof coating in orderto fluidly isolate the sensor material and the conductor(s) from thefluid contained within the system 50. In such an embodiment, the sensormaterial may correspond to any suitable material that undergoes adetectable change (e.g., a change in material or electrical properties)in response to variations in the pressure of the fluid exposed to thesensor 288, 289. For instance, the sensor material may correspond to anelectrically conductive polyimide film (e.g., KAPTON XC manufactured byDUPONT) that is configured to be positioned adjacent to the conductor(s)such that the contact area defined between the sensor material and theconductor(s) changes in response to variations in the fluid pressure dueto deformation of the sensor material, Specifically, in one embodiment,the contact area may increase with increases in the pressure. Suchincreases in the contact area between the sensor material and theconductor(s) may result in an increase in the conductivity of the sensor288, 289 and, thus, a decrease in the electrical resistance within thesensor 288, 289, which may then be detected and correlated to the fluidpressure within the system 50.

In embodiments in which each pressure sensor 288, 289 corresponds to apressure-sensitive film, it should be appreciated that the film maygenerally be placed at any suitable location that allows the film todirectly or indirectly monitor the pressure of the fluid suppliedthrough the system 50. For instance, in one embodiment, thepressure-sensitive film may be placed within the housing 204 such thatthe film extends directly into the flow path defined by each outlet port216, 218. For instance, FIG. 22 illustrates a cross-sectional view ofthe housing 204 shown in FIG. 15 taken about line 22,23-22,23,particularly illustrating one example of a suitable arrangement forpositioning a pressure-sensitive film within the flow path of the fluidbeing directed through the outlet ports 216, 218. As shown, each sensor288, 289 may be configured to extend outwardly from an inner surface 290of the corresponding outlet port 216, 218 such that thepressure-sensitive film is exposed to fluid along both its sides.Alternatively, the pressure-sensitive film may be positioned at anyother suitable location within and/or around the flow path of the fluidthrough the housing 204. For example, FIG. 23 illustrates anothercross-sectional view of the housing 204 shown in FIG. 15 taken aboutline 22,23-22,23, particularly illustrating another example of asuitable arrangement for positioning a pressure-sensitive film withinthe flow path of the fluid being directed through the outlet ports 216,218. As shown, each sensor 288, 289 may be configured to extend aroundthe inner circumference of its corresponding outlet port 216, 218 suchthat the fluid directed through the port 216, 218 contacts the filmalong its inner perimeter.

In other embodiments, the pressure sensors 288, 289 may be disposed atany other suitable location along the fluid flow path that allows thesensors 288, 289 to monitor the pressure of the fluid within the system50. For instance, in an alternative embodiment, a pressure sensor(indicated by dashed lines 291 in FIG. 12) may he provided in fluidcommunication with each valve tube 40, 42 extending between the actuatorassembly 20 and one of the valves 24, 26 to allow the pressure withineach valve tube 24, 26 to be monitor. In another embodiment, a pressuresensor may be provided in operative association with each valve 24, 26.For example, FIG. 24 illustrates a cross-sectional view of oneembodiment of a suitable configuration for associating a pressure sensor292 within each valve 24, 26. As shown, the valve 24, 26 may beconfigured similarly to the valve 24, 26 shown in FIGS. 10 and 11. Forexample, the valve 24, 26 may include a balloon 180 configured to beinflated (e.g., via fluid supplied thereto by the associated valve tube40, 42) within a cylindrical housing or sleeve 174. In addition, thevalve 24, 26 includes an outer sleeve 190 extending circumferentiallyaround the inner sleeve 174 so as to surround at least a portion of theinner sleeve 174. In such an embodiment, a pressure sensor 292 (e.g., apressure-sensitive film) may be installed between the inner and outersleeves 174, 190 so as to extend circumferentially around at least aportion of the area along which the inner sleeve 174 will be forcedoutwardly due to inflation of the balloon 180. As such, when the balloon180 is inflated and applies a radially outward force against the innersleeve 174, the pressure sensor 292 may be configured to detect suchforce, thereby providing an indication of the pressure within theballoon 180.

It should be appreciated that, as an alternative to the use of pressuresensitive films, the pressure sensors 288, 289 may correspond to anyother suitable sensors capable of detecting or sensing the pressure ofthe fluid supplied at any location within the disclosed system 50. Forinstance, suitable pressure sensors for use within the disclosed system50 may include, but are not limited to, pressure sensors utilizingpiezoresistive strain gauges and/or relying on capacitive,electromagnetic, piezoelectric, optical and/or potentiometric sensingtechniques.

Referring back to FIGS. 21-21, as indicated above, the actuator assembly200 may also include a sensor communications device 284 communicativelycoupled to the pressure sensors 228, 289 that is configured toreceive/store the sensor measurements transmitted from the sensor(s)288, 289 and/or wirelessly transmit such sensor measurements to aseparate wireless communication device positioned outside the patient'sbody. For example, as indicated above, the activator device 202 mayinclude a wireless communications device 278 incorporated therein forreceiving and/or transmitting wireless communications. As a result,wireless communications associated with the pressure measurementsreceived from the pressure sensor(s) 288, 289 may be transmitted fromthe sensor communications device 284 to the activator device 202.

In several embodiments, the sensor communications device 284 may includea suitable processor 293 (FIG. 15) (e.g., an integrated circuit) and anassociated antenna 294 (FIG. 15) for receiving and/or transmittingwireless communications. In such an embodiment, the sensorcommunications device 284 may be powered via an onboard battery, whichmay allow for data logging of the pressure sensor measurements.Alternatively, the sensor communications device 284 may be configured,to be remotely powered, thereby eliminating the requirement for abattery to be placed within the implanted actuator assembly 200. Forinstance, as described above, the sensor communications device 284 maybe configured to be powered via, a radio frequency (RF) field generatedby the NFC-equipped wireless communications device 278 of the activatordevice 202. In such instance, while power is being provided to theprocessor 293 via the electromagnetic field generated by the wirelesscommunication device 278, the sensor communications device 284 mayreceive sensor measurements from the pressure sensors 288, 289 and causesuch measurements to be transmitted wirelessly via the antenna 294. As aresult, the NFC powered communications device 284 may allow forinstantaneous or real time pressure measurements associated with thecurrent fluid pressure within the system 50 to be transmitted wirelesslyto the activator device 202 (or any other suitable device positionedexterior to the patient).

It should be appreciated that the antenna 294 associated with the sensorcommunications device 284 may generally be configured to providewireless communications via any suitable wireless communicationsprotocol. For instance, in one embodiment, the antenna 294 may allow forNEC-based communications to be transmitted from the sensorcommunications device 284. Alternatively, any other suitable wirelesscommunications protocol may be utilized, such as Bluetooth and/or thelike.

As indicated above, when the activator device 202 is placed in contactwith or adjacent to the patient's skin at a location directly above theactuator assembly 200 in order to magnetically drive the driver assembly210, the wireless communication device 278 of the activator device 202may also be used to simultaneously generate an electromagnetic fieldthat is capable of powering the sensor communications device 284. Thus,as the valves 24, 26 are being inflated via magnetic activation of thedriver assembly 210, the NFC-powered sensor communication device 284 maybe configured to receive instantaneous pressure measurements from thepressure sensor(s) 288, 289 and transmit such measurements to thewireless communication device 278. As indicated above, the pressuremeasurements received by the wireless communications device 278 may thenbe utilized to provide the operator with a visual indication of theinflation/deflation level of the valves 24, 26.

For example, as shown in FIG. 20, the activator device 202 may includean indicator bar 285 including a plurality of lights 295 configured tobe sequentially illuminated as the fluid pressure within the system 50increases. As a result, the indicator bar 285 may provide an indicationof the inflation/deflation level of the balloon valves 24, 26. Forinstance, the controller 270 of the activator device 202 may beconfigured to illuminate all of the lights 295 contained within theindicator bar 285 when the monitored fluid pressure indicates that theballoon valves 24, 26 are fully inflated and turn off all of the lights295 when the monitored fluid pressure indicates that the balloon valves24, 26 are fully deflated. Thus, as the operator is using the activatordevice 202 to inflate the balloons (i.e., to close the valves 24, 26),he/she may view the indicator bar 285 as additional lights 295 containedwithin the indicator bar 285 are illuminated with increases in the fluidpressure. When all of the lights 295 have been illuminated (therebyindicating that the balloons are fully inflated), the operator may turnoff the activator device 202 or otherwise move the device away from thepatient. Similarly, when the operator is using the activator device 202to deflate the balloons (i.e., to open the valves 24, 26), he/she mayview the indicator bar 285 as the lights 295 are sequentially turnedoff. When all of the lights 295 have been turned off (thereby indicatingthat the balloons are fully deflated), the operator may turn off theactivator device 202 or otherwise move the device away from the patient.

It should be appreciated that, in alternative embodiments, the activatordevice 202 may include any other suitable means for providing theoperator with an indication of the inflation/deflation level of theballoon valves 24, 26. For example, in one embodiment, the activatordevice 202 may incorporate a display panel (e.g., an LCD display panel)that may be used to display alphanumeric data, graphs and/or any othersuitable data that provides the operator with a visual indication of theinflation/deflation level of the valves 24, 26. In addition to visualindicators (or as an alternative thereto), the activator device 202 mayalso include one or more speakers for providing an audible indication ofthe inflation/deflation level of the valves 24, 26.

Moreover, in one embodiment, the controller 270 may be configuredautomatically control the operation of the activator device 202 based onthe pressure measurements received from the pressure sensors 288, 289.For example, the controller 270 may be configured to automatically turnoff the motor 258 when the pressure measurements received from thepressure sensors 288, 289 indicate that the valves 24, 26 have beenfully deflated (i.e., when opening the valves 24, 26 to begin thehemodialysis process) and/or fully inflated (i.e., when closing thevalves 24, 26 to complete the hemodialysis process).

Referring now to FIG. 25, another embodiment of an arteriovenous accessvalve system 350 is illustrated in accordance with aspects of thepresent subject matter. As shown, the system 350 may generally beconfigured similar to the system 50 described above with reference toFIG. 2. For instance, the system 350 may include an arteriovenous graft12 coupled between an artery 14 and a vein 16. In order to carry outhemodialysis, a first hypodermic needle 18 is inserted through the skinand into the arteriovenous graft 12. Blood is removed from thearteriovenous graft 12 through the needle and into a dialysis machine20. In the dialysis machine, waste materials are removed from the blood.After circulating through the dialysis machine 20, the blood is then fedback into the arteriovenous graft 12 through a second hypodermic needle22.

In addition, the system 350 may include a first valve 24 positioned ator adjacent to the arterial end of the arteriovenous graft 12 and asecond valve 26 positioned at or adjacent to the venous end of thearteriovenous graft. As indicated above, in several embodiments, thevalves 24, 26 may correspond to balloon-actuated valves and, thus, mayeach include an inflatable balloon (not shown). When inflated, theballoons close the valves 24, 26 in a manner that reduces or eliminatesthe blood flow through the graft 12. In contrast, when the balloons aredeflated, the valves 24, 26 are opened and blood may be directed throughthe arteriovenous graft 12.

However, unlike the system 50 described above, each valve 24, 26 may beconfigured to be in fluid communication with a separate actuatorassembly 300A, 300B for inflating/deflating its corresponding balloon.Specifically, as shown in the illustrated embodiment, the system 350 mayinclude a first actuator assembly 300A in fluid communication with thefirst valve 24 (e.g., via a first valve tube 40). Additionally, thesystem 350 may include a second actuator assembly 300B in fluidcommunication with the second valve 26 (e.g., via a second valve tube42). By providing a separate actuator assembly 300A, 300B in operativeassociation with each valve 24, 26, the valves 24, 26 may be opened andclosed independently. For example, when the hemodialysis process iscompleted, the valve positioned at the arterial end of the arteriovenousgraft 12 (e.g., the first valve 24) may be initially closed byactivating the first actuator assembly 300A. Thereafter, the valvepositioned at the venous end of the graft 12 (e.g., the second valve 26)may be closed by separately activating the second actuator assembly300A.

It should be appreciated that, in several embodiments, the actuatorassemblies 300A, 300B may correspond to magnetically activated actuatorassemblies. For instance, in one embodiment, each actuator assembly300A, 300B may be configured the same as or similar to the actuatorassembly 100 described above with reference to FIGS. 3-8 and/or theactuator assembly 200 described above with reference to FIGS. 12-19.

It should also be appreciated that, in alternative embodiments, thesystem 350 may include any other suitable means for independentlyopening and closing the valves 24, 26. For instance, as an alternativeto including two separate actuator assemblies, the system 350 mayinclude a single actuator assembly configured to independently open andclose each valve 24, 26. In such an embodiment, the actuator assemblymay, for example, include two separate screw/plunger drives and/or twoseparate gear pumps housed therein for independently supplying fluidinto and drawing fluid out of each valve 24, 26. Alternatively, thesingle actuator assembly may include a flow diverter (e.g., adirectional flow valve or other similar type of mechanism) that allowsthe flow of fluid to be diverted to each valve 24, 26 separately or toboth valves 24, 26 in combination.

Referring now to FIG. 26, a front view of one embodiment of an activatordevice 302 that may be utilized in association with the system 350 inorder to independently activate the valves 24, 26 is illustrated inaccordance with aspects of the present subject matter. In general, theactivator device 302 may be configured the same as or similar to theactivator device 202 described above with reference to FIGS. 12, 20 and21. For example, as shown, the activator device 302 may include areversible motor 258 rotatably coupled to one or more activator magnets260 positioned at and/or adjacent to a contact end 262 of the device302. Similar to the embodiments described above, the activator magnet(s)260 may, in turn, be configured to magnetically react with the drivemagnet of each actuator assembly 300A, 300B to allow fluid to betransported to and drawn back out of its corresponding valve 24, 26. Inaddition, the activator device 302 may include one or more internalcomponents (not shown) for facilitating desired operation of the device302, such as a battery (e.g., the battery 268 shown in FIG. 21), acontroller (e.g., the controller 270 shown in FIG. 21), a wirelesscommunications device (e.g., the wireless communications device 278shown in FIG. 21) and/or any other suitable internal components.

Moreover, similar to the activator device 202 described above, a toggleswitch 264 may be provided on the exterior of the activator device 302that can be toggled from a neutral or off position (e.g., the positionat which the motor 258 is turned off) to a forward or “inflation”position so as to cause the motor 258 to be rotated in a first directionand from the off position to a reverse or “deflation” position so as tocause the motor 258 to be rotated in the opposite direction.Additionally, the activator device 302 may also include an indicatorlight 266 that is configured to be illuminated in one or more colorswhen the toggle switch 264 is moved from the off position to theinflation or deflation position, thereby providing an indication of theoperational status and/or rotational direction the motor 258.

As shown in FIG. 26, unlike the embodiment described above withreference to FIGS. 12, 20 and 21, the activator device 302 may alsoinclude valve indicator lights 263, 265 for providing the operator withan indication of which actuator assembly 300A, 300B can be currentlycontrolled by the activator device 302. Specifically, as shown in theillustrated embodiment, the activator device 302 may include a firstvalve indicator light 263 that is configured to be illuminated when theactivator device 302 is placed adjacent to the first actuator assembly300A (e.g., by placing the activator device 302 in contact with oradjacent to the patient's skin at a location directly above the locationof the actuator assembly 300A). Similarly, the activator device 302 mayinclude a second valve indicator light 265 that is configured to beilluminated when the activator device 302 is placed adjacent to thesecond actuator assembly 300B (e.g., by placing the activator device 302in contact with or adjacent to the patient's skin at a location directlyabove the location of the actuator assembly 300B). As such, when thefirst valve indicator light 263 is illuminated, the operator may beprovided with an indication that the activator device 302 is properlypositioned for activating the first actuator assembly 300A, therebyallowing the first valve 24 to be opened and/or closed. Similarly, whenthe second valve indicator light 265 is illuminated, the operator may beprovided with an indication that the activator device 302 is properlypositioned for activating the second actuator assembly 300A, therebyallowing the second valve 26 to be opened and/or closed.

It should be appreciated that the valve indicator lights 263, 265 may betriggered using any suitable means known in the art. For instance, inone embodiment, the appropriate valve indicator light 263, 265 may beilluminated When the activator device 302 is placed sufficiently closeto one of the actuator assemblies 300A, 300B to allow an NFC-basedconnection to be established between the device 302 and such actuatorassembly 300A, 300B. Specifically, in embodiments in which the actuatorassemblies 300A, 300B are configured the same as or similar to theactuator assembly 200 described above, the activator device 302 may beconfigured to illuminate the valve indicator light 263, 265corresponding to the actuator assembly 300A, 300B from which pressuremeasurements are currently being received, thereby indicating that theactivator device 302 has been placed close enough to the actuatorassembly 300A, 300B in order to power its on-board sensor communicationsdevice 284 (FIG. 15) via NFC. For instance, when the activator device302 is placed adjacent to the first actuator assembly 300A, theproximity of the two components may allow the on-board sensorcommunications device 284 of the first actuator assembly 300A to bepowered and begin to wirelessly transmit pressure measurements to theactivator device 302. Upon receipt of the initial pressure measurements,the activator device 302 may then illuminate the first valve indicatorlight 263 to indicate to the operator that the activator device 302 maybe used to open and/or close the first valve 24.

Additionally, the activator device 302 may also include a suitable meansfor providing the operator with an indication of the inflation/deflationlevel of each valve 24, 26. For instance, as shown in FIG. 26, theactivator device 302 may include a first display panel 267 for providingan indication of the inflation/deflation level of the first valve 24 anda second display panel 269 for providing an indication of theinflation/deflation level of the second valve 26. By including suchdisplay panels 267, 269, the inflation/deflation levels of the valves24, 26 may be displayed to the operator separately, thereby allowing theoperator to cheek the individual status of each valve 24, 26 as itscorresponding actuator assembly 300A, 300B is being activated.

It should be appreciated that the display panels 267, 269 may generallycorrespond to any suitable display panel or device that allowsalphanumeric characters, images and/or any other suitable displayableitems to be presented to the operator. For instance, in one embodiment,the display panels 267, 269 may correspond to LCD display panels thatallow graphs, symbols, images and/or the like to be displayed to theoperator. Alternatively, each display panel 267, 269 may correspond to adevice that is simply configured to display a digital readout (e.g.,numerical values) corresponding to the inflation/deflation level of eachvalve 24, 26.

It should also be appreciated that, as an alternative to the displaypanels 267, 269, the activator device 302 may include any other suitablemeans for providing the operator with an indication of theinflation/deflation level of each valve 24, 26. For instance, similar tothe embodiment described above with reference to FIG. 20, the activatordevice 302 may include two separate pressure indicator bars, with eachindicator bar including a plurality of lights configured to beilluminated so as to provide a visual indication of theinflation/deflation level of its associated valve 24, 26.

Referring now to FIG. 27, a schematic view of another embodiment of anactuator assembly 400 that may be utilized within any of thearteriovenous access valve systems 50, 350 described herein isillustrated in accordance with aspects of the present subject matter. Aswill be described below, the illustrated actuator assembly 400 includesvarious different means for rotationally driving its associated driverassembly 410, thereby allowing fluid to be supplied to and/or drawn backout of the valves 24, 26 provided in fluid communication with theassembly 400.

In general, the actuator assembly 400 may be configured similar to theactuator assembly 200 described above with reference to FIGS. 12-19. Forexample, the actuator assembly 400 may include both a housing 404extending lengthwise between a first end 406 and a second end 408 and adriver assembly 410 located within the housing 404 between its first andsecond ends 406, 410. Similar to the embodiment described above, thedriver assembly 410 may generally correspond to a gear pump that, whenactivated, may be configured to pump or transport a suitable fluid(e.g., a saline solution) between a fluid reservoir (not shown) andcorresponding valves 24, 26 fluidly connected to the actuator assembly400. Additionally, as shown in the illustrated embodiment, the actuatorassembly 400 may include an inlet port 414 defined by and/or through aportion of the housing 404 (e.g., at the first end 406 of the housing404) and one or more outlet ports 416, 418 defined by and/or through adifferent portion of the housing 404 (e.g., at the second end 408 of thehousing 204). Moreover, as shown in FIG. 27, the actuator assembly 400may also include a back-up septum 486 (e.g., positioned at the first end406 of the housing 404) so as to provide a means for adding fluid intoand/or removing fluid from the actuator assembly 400.

In several embodiments, the driver assembly 410 may be configured to berotatably driven using one or more drive means associated with theactuator assembly 400. For example, similar to the embodiment describedabove with reference to FIGS. 12-19, the driver assembly 410 may beconfigured to be rotatably driven via a drive magnet 446 located withinthe housing 404. Specifically, as shown in FIG. 27, the drive magnet 446may be rotatably coupled to the driver assembly 410 via one or moredrive shafts 447. As such, when a rotating magnet is placed adjacent tothe actuator assembly 400 (e.g., the activator magnet 260 of theactivator device 202 shown in FIG. 12), the drive magnet 446 may berotated therewith, thereby rotationally driving the driver assembly 410and allowing fluid to be pumped out of the housing 404 (e.g., via theoutlets 416, 418) and supplied to the associated valves 24, 26 or pumpedback into the housing 404.

Additionally, as shown in FIG. 27, the actuator assembly 400 may alsoinclude a motor 449 rotatably coupled to the driver assembly 410, suchas by rotatably coupling the motor 449 between the drive magnet 446 andthe driver assembly 410 via the drive shaft(s) 447. In general, themotor 449 may be configured to serve as an additional drive means forthe driver assembly 410. Specifically, as an alternative to therotationally driving the drive magnet 446 via an external magnet, themotor 449 may be operated to allow the driver assembly 410 to berotationally driven.

To allow for control of the operation of the motor 449, the actuatorassembly 400 may also include a suitable controller 453 positionedwithin the housing 404. In several embodiments, the controller 453 maybe configured to control the operation of the motor 449 based onwireless control signals received from an external device (e.g., theactivator device 202). For instance, as shown in FIG. 27, the controller453 may be communicatively coupled to a suitable antenna 455 forreceiving wireless control signals. In such instance, if a wirelesscontrol signal is received by the controller 453 that indicates that thevalves 24, 26 are to be closed, the controller 453 may be configured tocontrol the motor 449 so that it is rotated in the appropriate directionfor pumping fluid to the valves 24, 26. Similarly, if a wireless controlsignal is received by the controller 453 that indicates that the valves24, 26 are to be opened, the controller 453 may be configured to controlthe motor 449 so that it is rotated in the opposite direction forpumping fluid out of the valves 24, 26.

As shown in FIG. 27, in one embodiment, power may be supplied to themotor 449 via an on-board battery 451. In such an embodiment, thebattery 451 may correspond to a rechargeable battery to allow thebattery 451 to be recharged when the driver assembly 410 is beingrotatable driven via the drive magnet 446. Specifically, when the drivemagnet 446 is being rotated using an external magnet drive, the motor449 may serve as a generator for producing electricity for rechargingthe battery 451.

In addition to powering the motor 449 via the battery 451 for as analternative thereto), the motor 449 may be configured to be poweredindirectly via a remote power source. For example, similar to the sensorcommunications device 284 described above, the controller 453 may beconfigured to be powered via a remote NFC-equipped device (e.g., theactivator device 202). In such instance, the NFC-powered controller 453may be configured to supply a sufficient amount of power to the motor449 to allow the motor 449 to rotationally drive the driver assembly410.

It should be appreciated that various embodiments of componentsconfigured for use within an arteriovenous access valve system 50, 350have been described herein in accordance with aspects of the presentsubject matter. In this regard, one of ordinary skill in the art shouldreadily appreciate that various different combinations of systemcomponents may be utilized within any given system configuration. Forexample, the pressure sensors 288, 289 may also be utilized within thesystem. 50 described above with reference to FIGS. 3-9. For instance,the pressure sensors 288, 289 may be installed within the housing 104 ofthe actuator assembly 100 (e.g., at or adjacent to the outlet ports 118,120) and/or may be provided in operative association with the valvetubes 40, 42 and/or corresponding valves 24, 26. In such an embodiment,the actuator assembly 100 may also include a sensor communicationsdevice for wirelessly transmitting the pressure measurements receivedfrom the sensors 288, 289 to a separate device located exterior to thepatient. For instance, similar to the activator device 202 shown inFIGS. 12, 20 and 21, the activator device 102 may include a wirelesscommunications device for receiving pressure measurements from theimplanted actuator assembly 100.

Additionally, as indicated above, it should be appreciated that thepresent subject matter is also directed to a method for operating anarteriovenous access valve system 50, 350. For example, in oneembodiment, the method may include positioning an external activatordevice 102, 202, 302 in proximity to an implanted actuator assembly 100,200, 300A, 300B, 400 of the system and rotating a magnet of theactivator device 102, 202, 302 while the activator device 102, 202, 302is positioned adjacent to the implanted actuator assembly 100, 200,300A, 300B, 400 so as to rotationally drive a driver assembly 110, 210,410 of the implanted actuator assembly 100, 200, 300A, 300B, 400 andmoving the activator device 102, 202, 302 away from the implantedactuator assembly 100, 200, 300A, 300B, 400 after the driver assembly110, 210, 410 has been rotatably driven for a period of time. Forinstance, the driver assembly 110, 210, 410 may be rotatably driven fora period of time corresponding to the time required to open and/or closethe associated valve(s) 24, 26.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

I claim:
 1. A power system for an arteriovenous access valve systemincluding a first valve configured to be positioned at or adjacent to anend of an arteriovenous graft; a second valve configured to bepositioned at or adjacent to an opposite end of the arteriovenous graft;an actuator assembly in fluid communication with the first and secondvalves, the actuator assembly including a housing and a driver assemblypositioned within the housing, the actuator assembly further including adrive magnet positioned within the housing, the drive magnet beingrotatably coupled to the driver assembly such that, when the drivemagnet is rotated, the driver assembly is configured to be rotatablydriven so as to supply fluid to the first and second valves or to drawfluid out of the first and second valves depending on a rotationaldirection of the driver assembly; at least one pressure sensorconfigured to monitor a pressure of the fluid supplied between theactuator assembly and the first and second valves; and a sensorcommunications device communicatively coupled to the at least onepressure sensor, the sensor communications device being configured towirelessly transmit pressure measurements provided by the at least onepressure sensor to a separate communications device, the power systemcomprising: a separate device spaced from the actuator assemblyconfigured to power remotely the sensor communications device.
 2. Thepower system of claim 1, wherein the separate device includes aninitiator device configured for near field communication.
 3. The powersystem of claim 2, wherein the initiator device generates aradiofrequency field.
 4. The power system of claim 2, wherein the sensorcommunications device includes a near field communication receiver.
 5. Apower system for an arteriovenous access valve system including a firstvalve configured to be positioned at or adjacent to an end of anarteriovenous graft; a second valve configured to be positioned at oradjacent to an opposite end of the arteriovenous graft; an actuatorassembly in fluid communication with the first and second valves, theactuator assembly including a housing and a driver assembly positionedwithin the housing; at least one pressure sensor configured to monitor apressure of the fluid supplied between the actuator assembly and thefirst and second valves; and an activator device including an activatormagnet, the activator device being configured to rotate the activatormagnet so as to rotationally drive the driver assembly, wherein thedriver assembly is configured to supply fluid to the first and secondvalves or draw fluid out of the first and second valves depending on arotational direction at which the driver assembly is being driven; asensor communications device communicatively coupled to the at least onepressure sensor, the sensor communications device being configured towirelessly transmit pressure measurements provided by the at least onepressure sensor to a wireless communications device of the activatordevice, the power system comprising: an initiator device located in theactivator device configured to power remotely the sensor communicationsdevice.
 6. The power system of claim 5, wherein the initiator device isconfigured for near field communication.
 7. The power system of claim 6,wherein the initiator device generates a radiofrequency field.
 8. Thepower system of claim 6, wherein the sensor communications deviceincludes a near field communication receiver.
 9. A method for powering acommunications system of an arteriovenous access valve system, thearteriovenous access valve system including an implemented actuatorassembly in fluid communication with first and second valves, anexternal activator device including a rotatable magnet rotated while theexternal activator device is positioned adjacent to the implantedactuator assembly so as to rotationally drive a driver assembly of theimplanted actuator assembly, the driver assembly being configured tosupply fluid to the first and second valves or draw fluid out of thefirst and second valves depending on a rotational direction at which thedriver assembly is being driven, the implanted actuator assemblymonitoring a pressure of the fluid supplied between the actuatorassembly and the first and second valves while the driver assembly isbeing rotatably driven and wirelessly transmitting via a sensorcommunications device the pressure monitored to a separate device, themethod for powering including: generating a near field communicationsignal in the activator device to power remotely the sensorcommunications device.
 10. The method of claim 9, wherein the near fieldcommunication signal is a radiofrequency field.
 11. The method of claim9, wherein the sensor communications device includes a near fieldcommunication receiver.